Carton latch



L. A. HEINTZELMAN CARTON LATCH Filed April 2, 1962 INVENTOR LEO A.HEINTZELMAN u/Oqa, mew, 1611mm ATTvLsj United States Patent Office3,144,973 Patented Aug. 18, 1964 3,144,973 CARTON LATCH Lee A.Heintzelman, 4990 Burlingame Ave, Grandville, Mich, assignor of one-halfto Herman Wilbert, Grand Rapids, Mich.

Filed Apr. 2, 1962, Ser. No. 184,335 2 tClairns. (Cl. 229-2.5)

This invention relates generally to egg cartons, and more particularly,to an improved latching device for egg cartons formed of molded pulpfiber.

It is a primary object of the present invention to provide a simple andpositive device for latching the hinged cover of an egg carton to itscellular base portion.

It is a more particular object to provide such a latching device inwhich the mating parts may be formed integrally and contemporaneouslywith the formation of the carton.

Another object is to provide a latching device of the above type whichwill not accidentally unlock when the carton is lifted by its cover, butrather, the latch will become more firmly engaged under suchcircumstances.

It is also an object to provide a latching device as described abovewhich may be conveniently snapped into engagement and which may bereadily disengaged at a later time by a simple squeezing action whichmay be performed with one hand by the operator.

Other objects and advantages of the invention will become apparent uponreading the following detailed description and upon reference to thedrawings in which:

FIGURE 1 is a front elevation of a typical 3 x 4 style egg cartonincorporating the latching device of the present invention;

FIG. 2 is an enlarged partial section taken along the line 2-2 in FIG. 1showing the cross section of the latching mechanism;

FIG. 3 is a fragmentary front elevation of the carton cover showing thelatching opening; and

FIG. 4 is a fragmentary front elevation of the inner flap and latchingdevice.

While the invention will be described in connection with a preferredembodiment, it will be understood that I do not intend to limit theinvention to that embodi ment. On the contrary, I intend to cover allalternatives, modifications and equivalents as may be included withinthe spirit and scope of the invention as defined by the appended claims.

Turning now to the drawings there is shown a molded pulp fiber eggcarton indicated generally at having a body portion 11 and a coverportion 12. The body portion 11 is formed, in this instance, in thecustomary 3 x 4 style having three rows of four individual pockets orcells 13 into which the eggs may be placed and protected from oneanother. The cover portion 12 is preferably formed with a non-cellularor open tray-like construction with a rectangular top portion 14 whichmerges into four depending wall members shaped similarly to a front wall15 as shown in FIG. 1.

The body portion 11 and cover portion 12 are each formed with respectiveflanges 16 and 17 which extend laterally from the open edges of therespective portions 11, 12. The flanges 16, 17 thus serve to providesubstantial seating or bearing surfaces for the cover 12 upon the body11 when the carton 10 is closed. It will also be appreciated that theflanges 16, 17 may be interconnected or formed integrally with oneanother along one edge of the carton so as to provide a hinge betweenthe cover 12 and the body 11 of the carton 10.

In accordance with the present invention, a two part latching device 20is formed integrally with the respective body portion 11 and coverportion 12 of the carton to provide a positive lock when the carton isclosed. In the preferred embodiment, the latching member 20 includes anupstanding tang or locking tab 21 which is formed contiguously with thefront wall 15 and which projects upwardly into a latch opening 22 in thefront wall. A mating latch 23 is carried by and projects from an innerflap 24 hinged to the front edge of the body portion 11. The flap 24 isprovided with an offset flange construction 25 adjacent the hingedconnection to the body portion 11 in such a way that the flange 17 ofthe cover portion 12 will rest against it when the cover is closed. Theflap member 23 projects upwardly inside the front wall 15 inface-to-face relationship therewith (see FIG. 2). The projecting catch23 is located on the flap 24 so that it will register with the latchopening 22 when the cover 11 is closed. A slot 26 is formed in a lowerprojecting surface of the catch 23 substantially the same length as thewidth of the tab 21.

As the cover 12 is closed the Wall 15 is telescoped downwardly over theinner flap 24. When the cover flange 17 engages the ofiset flange 25,the flap is sprung outwardly tending to urge the projecting catchthrough the latching opening 22. However, since the locking tab 21projects upwardly into the opening 22, the catch 23 may not enter theopening until additional pressure is applied to the top 14 of the cover12. The additional pressure applied to the cover 12 allows the catch 23to spring outwardly and upwardly through the opening 22 and as thepressure is released, the slot 26 engages the locking tab 21.

To disengage the latching mechanism 20, it is only necessary for theoperator to grasp the lower portion 27 of the catch 23 and the top 14 ofthe cover 12 between his finger and thumb and squeeze these partstogether. This lifts the catch 23 over the locking tab 21 and the normalrearward pressure exerted by the squeezing action urges the catch 23inwardly of the opening 22.

It may also be appreciated that the construction of the latching device20 prevents accidental opening of the carton 10 when it is lifted by itscover portion 12. Thus, it will be seen that lifting the cover portion12 serves to carry the locking tab 21 upwardly thereby seating it morefirmly within the slot 26. Therefore, while it is not desirable to liftsuch cartons by grasping only the top portion, it will be seen that thepresent latching mechanism 20 prevents the carton from springing openand thereby spilling its contents.

The construction employed in the preferred embodiment of the latchingdevice 20 also allows the carton 10 to be formed in a one-stepoperation. Thus, since the locking tab 21 is formed contiguously withthe front wall 15 of the cover 12 and the projecting catch 23 isintegrally formed on the flap 24, it is possible to mold the carton witha single set of dies. In this way, a latching device which is bothpositive in locking the carton and yet simple to engage and disengagemay be formed very economically with little or no additional cost overthat of the carton itself.

I claim as my invention:

1. A molded pulp fiber egg carton comprising a pocketed body section forholding a plurality of eggs, and an overlying tray-like cover section,flanges formed on each of said sections adjacent the edges thereof, saidflanges being interconnected along the rear edges of said sectionsforming a hinge therebetween, an inner flap member hinged at its lowerportion to the front edge of said body section and projecting upwardlytherefrom in face-to-face relationship with a front wall of said coversection when the cover is closed over said body section, said front wallhaving an opening therein and having a contiguously formed upstandinglocking tab projecting partially into said opening, said inner flaphaving an outwardly projecting catch member adapted to register with aand insertable laterally into said opening without distortion when saidcover section is closed, and a slot in the lower portion of said catchmember to receive said locking tab when said catch member is insertedinto said opening and after movement thereof downwardly in said 5opening into latching position to prevent movement of said catch memberlaterally of said opening.

2. A molded pulp fiber egg carton as defined in claim 1 wherein saidlocking tab projects into the opening in said front wall medially of thewidth of the opening and said 10 11 slot is disposed medially of theends of said outwardly projecting catch member.

References Cited in the file of this patent UNITED STATES PATENTS

1. A MOLDED PULP FIBER EGG CARTON COMPRISING A POCKETED BODY SECTION FORHOLDING A PLURALITY OF EGGS, AND AN OVERLYING TRAY-LIKE COVER SECTION,FLANGES FORMED ON EACH OF SAID SECTIONS ADJACENT THE EDGES THEREOF, SAIDFLANGES BEING INTERCONNECTED ALONG THE REAR EDGES OF SAID SECTIONSFORMING A HINGE THEREBETWEEN, AN INNER FLAP MEMBER HINGED AT ITS LOWERPORTION TO THE FRONT EDGE OF SAID BODY SECTION AND PROJECTING UPWARDLYTHEREFROM IN FACE-TO-FACE RELATIONSHIP WITH A FRONT WALL OF SAID COVERSECTION WHEN THE COVER IS CLOSED OVER SAID BODY SECTION, SAID FRONT WALLHAVING AN OPENING THEREIN AND HAVING A CONTIGUOUSLY FORMED UPSTANDINGLOCKING TAB PROJECTING